Oneida Main

Bear River· Franklin, Idaho· Built 1920· Concrete· 114 ft tall

High Hazard Irrigation Recreation Hydroelectric Private

Key Takeaway

Oneida Main is classified as high hazard in Idaho. It was completed in 1920 and is 106 years old. Its primary use is irrigation. High hazard means loss of life is likely if the dam fails — it does not indicate the dam's current condition. Learn more.

Physical Details

Dam Height	114 ft (taller than 94.6% in ID)
Dam Length	420 ft
Dam Type	Concrete
Max Storage	19.0K acre-ft
Normal Storage	10.9K acre-ft

Surface Area	357 acres
Drainage Area	4,456 sq mi
Max Discharge	74,270 cfs
Year Completed	1920 (106 years old)
NID ID	ID00068

Safety Information

High Hazard

Loss of human life is likely if the dam fails.

Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?

Emergency Action Plan: Yes

Last Inspection: June 29, 2022

State Regulated: Yes

Regulatory Agency: IDWR

Ownership

PacifiCorp

Private

Nearby Dams

Oneida Dike

Franklin, ID

High Hazard 47 ft

Andreasen Lower

Franklin, ID

Significant Hazard 33 ft

Andreasen Upper

Franklin, ID

Significant Hazard 29 ft

Strong Arm No 1 (Upper)

Franklin, ID

High Hazard 39 ft

Condie

Franklin, ID

Significant Hazard 41 ft

Casperson

Franklin, ID

Low Hazard 22 ft

Strong Arm No 2 (Lower)

Franklin, ID

Significant Hazard 27 ft

Winder

Franklin, ID

Significant Hazard 57 ft

Frequently Asked Questions

What is the hazard classification of Oneida Main?

Oneida Main is classified as High Hazard. Loss of human life is likely if the dam fails. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Oneida Main?

Oneida Main is owned by PacifiCorp (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Oneida Main built?

Oneida Main was completed in 1920, making it 106 years old. Many U.S. dams were built between the 1930s and 1970s during a period of major infrastructure investment.

What is the primary purpose of Oneida Main?

Oneida Main serves the following purposes: Irrigation, Recreation, Hydroelectric. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Oneida Main?

Oneida Main has a dam height of 114 ft. Dam height is measured from the natural streambed at the downstream toe to the top of the dam, and may differ from the visible height.

When was Oneida Main last inspected?

Oneida Main was last inspected on June 29, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.

Data from the National Inventory of Dams (NID) maintained by the US Army Corps of Engineers. Dam conditions may have changed since the last update. This site is not affiliated with USACE. Do not use for emergency planning — contact your local dam safety program.